Integrated process and catalysts for manufacturing hydrogen iodide from hydrogen and iodine

ABSTRACT

The present invention provides a process for producing hydrogen iodide. The process includes providing a vapor-phase reactant stream comprising hydrogen and iodine and reacting the reactant stream in the presence of a catalyst to produce a product stream comprising hydrogen iodide. The catalyst includes at least one selected from the group of nickel, cobalt, iron, nickel oxide, cobalt oxide, and iron oxide. The catalyst is supported on a support.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. Pat. Application No.16/849,213, filed Apr. 15, 2020, which claims priority to U.S.Provisional Application Nos. 62/834,849, filed Apr. 16, 2019, and62/949,135, filed Dec. 17, 2019, all of which are herein incorporated byreference in their entireties.

FIELD

The present disclosure relates to a process for producing hydrogeniodide. Specifically, the present disclosure relates to a process forproducing anhydrous hydrogen iodide from hydrogen and iodine in thepresence of a catalyst.

BACKGROUND

Hydrogen iodide is an important industrial chemical used as a reducingagent, as well as in the preparation of hydroiodic acid, organic andinorganic iodides, iodoalkanes. However, hydrogen iodide is verydifficult to handle due to its instability and reactivity. For example,hydrogen iodide decomposes in the presence of heat or light to formhydrogen and iodine. Additionally, in the presence of moisture, hydrogeniodide forms hydroiodic acid which can corrode most metals. Theinstability and reactivity of hydrogen iodide makes it hard to store andto transport. As such, anhydrous hydrogen iodide is often preparedlocally for immediate use.

Various methods have been reported for making hydrogen iodide. See, forexample, N. N. Greenwood et al., The Chemistry of the Elements, 2ndedition, Oxford: Butterworth-Heineman. p 809-815, 1997, in whichhydrogen iodide is prepared from the reaction of elemental iodine withhydrazine according to Equation 1 below:

In another example, in Textbook of Practical Organic Chemistry, 3^(rd)edition, A. I. Vogel teaches that hydrogen iodide can be prepared byreacting a stream of hydrogen sulfide with iodine according to Equation2 below:

Each of the above examples use costly starting materials, such ashydrogen sulfide or hydrazine, that restrict their application for largescale, economical preparation of hydrogen iodide. Additionally, the useof hydrazine for preparation of hydrogen iodide results in the formationof nitrogen gas as a byproduct. Separation of the nitrogen gas from thehydrogen iodide to purify the hydrogen iodide is difficult andexpensive, thus adding to manufacturing costs. Similarly, the use ofhydrogen sulfide results in the formation of sulfur, which is difficultto separate from unreacted iodine, again adding to manufacturing costs.Sulfur may poison any catalysts used, further adding to manufacturingcosts.

In some other examples, hydrogen iodide is prepared from elementaliodine and hydrogen gas, according to Equation 3 below:

Such examples can more easily produce high-purity hydrogen iodide as nonitrogen or sulfur is produced. For instance, JP4713895B2 demonstratesthe preparation of hydrogen iodide in the gas phase using hydrogen gasand iodine vapor, catalyzed by noble metal-based catalysts.Specifically, the disclosed reaction can be catalyzed by platinum,rhodium, palladium, and ruthenium supported on metal oxides selectedfrom magnesium oxide, titanium oxide, silica oxide, alumina andzirconia. However, the use of noble metal-based catalysts forpreparation of hydrogen iodide would further increase manufacturingcosts due to the generally high cost of noble metals. Thus, there isneed for alternative metal catalysts that do not contain a noble metalfor catalyzing the reaction of hydrogen and iodine to make hydrogeniodide.

SUMMARY

The present disclosure provides an integrated process for themanufacture of hydrogen iodide (HI) from hydrogen (H₂) and elementaliodine (I₂) that includes the use of a catalyst including at least oneselected from the group of nickel, cobalt, iron, nickel oxide, cobaltoxide, and iron oxide supported on a support.

In one embodiment, the present invention provides a process forproducing hydrogen iodide. The process includes providing a vapor-phasereactant stream comprising hydrogen and iodine and reacting the reactantstream in the presence of a catalyst to produce a product streamcomprising hydrogen iodide. The catalyst includes at least one selectedfrom the group of nickel, cobalt, iron, nickel oxide, cobalt oxide, andiron oxide. The catalyst is supported on a support.

In another embodiment, the present invention provides a process forproducing hydrogen iodide. The process includes the steps of reactinghydrogen and iodine in the vapor phase in the presence of a catalyst toproduce a product stream comprising hydrogen iodide and unreactediodine, removing at least some of the unreacted iodine from the productstream by cooling the product stream to form solid iodine, producingliquid iodine from the solid iodine, and recycling the liquified iodineto the reacting step. The solid iodine forms in a first iodine removalvessel or a second iodine removal vessel. The liquid iodine is producedfrom the solid iodine by heating the first iodine removal vessel toliquefy the solid iodine when cooling the product stream through thesecond iodine removal vessel or heating the second iodine removal vesselto liquefy the solid iodine when cooling the product stream through thefirst iodine removal vessel. The catalyst includes at least one selectedfrom the group of nickel, cobalt, iron, nickel oxide, cobalt oxide, andiron oxide. The catalyst is supported on a support.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a process flow diagram showing an integrated process formanufacturing anhydrous hydrogen iodide.

FIG. 2 is a process flow diagram showing another integrated process formanufacturing anhydrous hydrogen iodide.

DETAILED DESCRIPTION

The present disclosure provides an integrated process for themanufacture of anhydrous hydrogen iodide (HI) from hydrogen (H₂) andelemental iodine (I₂) that includes the use of a nickel, cobalt, iron,nickel oxide, cobalt oxide, and/or iron oxide catalyst supported on asupport. It has been found that the use of such a catalyst provides forthe efficient manufacture of hydrogen iodide on a commercial scale. Theefficiency of the manufacture of the hydrogen iodide is further enhancedby the recycling of the reactants. Recycling of elemental iodine isparticularly important because it is an expensive raw material with abulk price of about $20 to $100 per kilogram. However, recycling iodinepresents challenges because it is solid below 113.7° C. The presentdisclosure also provides integrated processes for the manufacture ofhydrogen iodide that include recycling of iodine in an efficient andcontinuous manner.

As disclosed herein, the anhydrous hydrogen iodide is produced from areactant stream comprising hydrogen (H₂) and iodine (I₂). The reactantstream may consist essentially of hydrogen, iodine and recycled hydrogeniodide. The reactant stream may consist of hydrogen, iodine and hydrogeniodide.

The term “anhydrous hydrogen iodide” means hydrogen iodide that issubstantially free of water. That is, any water in the anhydroushydrogen iodide is in an amount by weight less that about 500 ppm, about300 ppm, about 200 ppm, about 100 ppm, about 50 ppm, about 30 ppm, about20 ppm, about 10 ppm, about 5 ppm, about 3 ppm, about 2 ppm, or about 1ppm, or less than any value defined between any two of the foregoingvalues. Preferably, the anhydrous hydrogen iodide comprises water byweight in an amount less than about 100 ppm. More preferably, theanhydrous hydrogen iodide comprises water by weight in an amount lessthan about 10 ppm. Most preferably, the anhydrous hydrogen iodidecomprises water by weight in an amount less than about 1 ppm.

It is preferred that there be as little water in the reactant stream aspossible because the presence of moisture results in the formation ofhydroiodic acid, which is corrosive and can be detrimental to downstreamequipment and process lines. In addition, recovery of the hydrogeniodide from the hydroiodic acid adds to the manufacturing costs.

The hydrogen is substantially free of water, including any water byweight in an amount less than about 500 ppm, about 300 ppm, about 200ppm, about 100 ppm, about 50 ppm, about 30 ppm, about 20 ppm, 10 ppm, orabout 5 ppm, or less than any value defined between any two of theforegoing values. Preferably, the hydrogen comprises any water by weightin an amount less than about 50 ppm. More preferably, the hydrogencomprises any water by weight in an amount less than about 10 ppm. Mostpreferably, the hydrogen comprises any water by weight in an amount lessthan about 5 ppm.

The hydrogen is substantially free of oxygen. That is, any oxygen in thehydrogen is in an amount by weight less than about 500 parts permillion, about 300 ppm, about 200 ppm, about 100 ppm, about 50 ppm,about 30 ppm, about 20 ppm, about 10 ppm, about 5 ppm, about 3 ppm,about 2 ppm, or about 1 ppm, or less than any value defined between anytwo of the foregoing values. Preferably, the amount of oxygen by weightin the hydrogen is less than about 100 ppm. More preferably, the amountof oxygen by weight in the hydrogen is less than about 10 ppm. Mostpreferably, the amount of oxygen by weight in the hydrogen is less thanabout 1 ppm. It is preferred that there be as little oxygen in thehydrogen as possible because the oxygen can react with the hydrogen toform water.

The iodine is also substantially free of water, including any water byweight in an amount less than about 500 ppm, about 300 ppm, about 200ppm, about 100 ppm, about 50 ppm, about 30 ppm, about 20 ppm, or about10 ppm, or less than any value defined between any two of the foregoingvalues. Preferably, the iodine comprises any water by weight in anamount less than about 100 ppm. More preferably, the iodine comprisesany water by weight in an amount less than about 30 ppm. Mostpreferably, the iodine comprises any water by weight in an amount lessthan about 10 ppm.

Elemental iodine in solid form is commercially available from, forexample, SQM, Santiago, Chile, or Kanto Natural Gas Development Co.,Ltd, Chiba, Japan. Hydrogen in compressed gas form is commerciallyavailable from, for example, Airgas, Radnor, PA, or from Air Productsand Chemicals, Inc., Allentown, PA.

In the reactant stream, a mole ratio of hydrogen to iodine may be as lowas about 1:1, about 1.5:1, about 2:1, about 2.5:1, about 2.7:1, or about3:1, or as high as about 4:1, about 5:1, about 6:1, about 7:1, about8:1, about 9:1, or about 10:1, or within any range defined between anytwo of the foregoing values, such as about 1:1 to about 10:1, about 2:1to about 8:1, about 3:1 to about 6:1, about 2:1 to about 5:1, about 2:1to about 3:1, about 2.5:1 to about 3:1, or about 2.7:1 to about 3.0:1,for example. Preferably, the mole ratio of hydrogen to iodine is fromabout 2:1 to about 5:1. More preferably, the mole ratio of hydrogen toiodine is from about 2:1 to about 3:1. Most preferably, the mole ratioof hydrogen to iodine is from about 2.5:1 to 3:1.

The reactant stream reacts in the presence of a catalyst containedwithin a reactor to produce a product stream comprising anhydroushydrogen iodide according to Equation 3 above. The reactor may be aheated tube reactor, such as a fixed bed tubular reactor, including atube containing the catalyst. The tube may be made of a metal such asstainless steel, nickel, and/or a nickel alloy, such as anickel-chromium alloy, a nickel-molybdenum alloy, anickel-chromium-molybdenum alloy, a nickel-iron-chromium alloy, or anickel-copper alloy. The tube reactor is heated, thus also heating thecatalyst. Alternatively, the reactor may be any type of packed reactor,such as a multi-tubular reactor (e.g. a shell-and-tube reactor) in whichthe catalyst is packed into the tubes and with a heat transfer medium incontact with the outside of the tubes, for example. The reactor mayoperate isothermally or adiabatically.

As noted above, the catalyst is a nickel, cobalt, iron, nickel oxide,cobalt oxide, and/or iron oxide catalyst on a support. Thus, thecatalyst comprises at least one selected from the group of nickel,cobalt, iron, nickel oxide, cobalt oxide, and iron oxide, wherein thecatalyst is supported on a support. The support can be selected from thegroup of activated carbon, silica gel, zeolite, silicon carbide, metaloxides, and combinations thereof. Non-exclusive examples of the metaloxides include alumina, magnesium oxide, titanium oxide, zinc oxide,zirconia, chromia, and combinations thereof.

The catalyst can comprise nickel on a silica gel support. The catalystcan comprise nickel on a zeolite support. The catalyst can comprisenickel on an activated carbon support. The catalyst can comprise nickelon a silicon carbide support. The catalyst can consist essentially ofnickel on a silica gel support. The catalyst can consist essentially ofnickel on a zeolite support. The catalyst can consist essentially ofnickel on an activated carbon support. The catalyst can consistessentially of nickel on a silicon carbide support. The catalyst canconsist of nickel on a silica gel support. The catalyst can consist ofnickel on a zeolite support. The catalyst can consist of nickel on anactivated carbon support. The catalyst can consist of nickel on asilicon carbide support.

The catalyst can comprise nickel on a metal oxide support. The catalystcan consist essentially of nickel on a metal oxide support. The catalystcan consist of nickel on a metal oxide support. The catalyst cancomprise nickel on an alumina support. The catalyst can comprise nickelon a magnesium oxide support. The catalyst can comprise nickel on atitanium oxide support. The catalyst can comprise nickel on a zinc oxidesupport. The catalyst can comprise nickel on a zirconia support. Thecatalyst can comprise nickel on a chromia support. The catalyst canconsist essentially of nickel on an alumina support. The catalyst canconsist essentially of nickel on a magnesium oxide support. The catalystcan consist essentially of nickel on a titanium oxide support. Thecatalyst can consist essentially of nickel on a zinc oxide support. Thecatalyst can consist essentially of nickel on a zirconia support. Thecatalyst can consist essentially of nickel on a chromia support. Thecatalyst can consist of nickel on an alumina support. The catalyst canconsist of nickel on a magnesium oxide support. The catalyst can consistof nickel on a titanium oxide support. The catalyst can consist ofnickel on a zinc oxide support. The catalyst can consist of nickel on azirconia support. The catalyst can consist of nickel on a chromiasupport.

The catalyst can comprise nickel oxide on a silica gel support. Thecatalyst can comprise nickel oxide on a zeolite support. The catalystcan comprise nickel oxide on an activated carbon support. The catalystcan comprise nickel oxide on a silicon carbide support. The catalyst canconsist essentially of nickel oxide on a silica gel support. Thecatalyst can consist essentially of nickel oxide on a zeolite support.The catalyst can consist essentially of nickel oxide on an activatedcarbon support. The catalyst can consist essentially of nickel oxide ona silicon carbide support. The catalyst can consist of nickel oxide on asilica gel support. The catalyst can consist of nickel oxide on azeolite support. The catalyst can consist of nickel oxide on anactivated carbon support. The catalyst can consist of nickel oxide on asilicon carbide support.

The catalyst can comprise nickel oxide on a metal oxide support. Thecatalyst can consist essentially of nickel oxide on a metal oxidesupport. The catalyst can consist of nickel oxide on a metal oxidesupport. The catalyst can comprise nickel oxide on an alumina support.The catalyst can comprise nickel oxide on a magnesium oxide support. Thecatalyst can comprise nickel oxide on a titanium oxide support. Thecatalyst can comprise nickel oxide on a zinc oxide support. The catalystcan comprise nickel oxide on a zirconia support. The catalyst cancomprise nickel oxide on a chromia support. The catalyst can consistessentially of nickel oxide on an alumina support. The catalyst canconsist essentially of nickel oxide on a magnesium oxide support. Thecatalyst can consist essentially of nickel oxide on a titanium oxidesupport. The catalyst can consist essentially of nickel oxide on a zincoxide support. The catalyst can consist essentially of nickel oxide on azirconia support. The catalyst can consist essentially of nickel oxideon a chromia support. The catalyst can consist of nickel oxide on analumina support. The catalyst can consist of nickel oxide on a magnesiumoxide support. The catalyst can consist of nickel oxide on a titaniumoxide support. The catalyst can consist of nickel oxide on a zinc oxidesupport. The catalyst can consist of nickel oxide on a zirconia support.The catalyst can consist of nickel oxide on a chromia support.

The catalyst can comprise nickel and nickel oxide on a silica gelsupport. The catalyst can comprise nickel and nickel oxide on a zeolitesupport. The catalyst can comprise nickel and nickel oxide on anactivated carbon support. The catalyst can comprise nickel and nickeloxide on a silicon carbide support. The catalyst can consist essentiallyof nickel and nickel oxide on a silica gel support. The catalyst canconsist essentially of nickel and nickel oxide on a zeolite support. Thecatalyst can consist essentially of nickel and nickel oxide on anactivated carbon support. The catalyst can consist essentially of nickeland nickel oxide on a silicon carbide support. The catalyst can consistof nickel and nickel oxide on a silica gel support. The catalyst canconsist of nickel and nickel oxide on a zeolite support. The catalystcan consist of nickel and nickel oxide on an activated carbon support.The catalyst can consist of nickel and nickel oxide on a silicon carbidesupport.

The catalyst can comprise nickel and nickel oxide on a metal oxidesupport. The catalyst can consist essentially of nickel and nickel oxideon a metal oxide support. The catalyst can consist of nickel and nickeloxide on a metal oxide support. The catalyst can comprise nickel andnickel oxide on an alumina support. The catalyst can comprise nickel andnickel oxide on a magnesium oxide support. The catalyst can comprisenickel and nickel oxide on a titanium oxide support. The catalyst cancomprise nickel and nickel oxide on a zinc oxide support. The catalystcan comprise nickel and nickel oxide on a zirconia support. The catalystcan comprise nickel and nickel oxide on a chromia support. The catalystcan consist essentially of nickel and nickel oxide on an aluminasupport. The catalyst can consist essentially of nickel and nickel oxideon a magnesium oxide support. The catalyst can consist essentially ofnickel and nickel oxide on a titanium oxide support. The catalyst canconsist essentially of nickel and nickel oxide on a zinc oxide support.The catalyst can consist essentially of nickel and nickel oxide on azirconia support. The catalyst can consist essentially of nickel andnickel oxide on a chromia support. The catalyst can consist of nickeland nickel oxide on an alumina support. The catalyst can consist ofnickel and nickel oxide on a magnesium oxide support. The catalyst canconsist of nickel and nickel oxide on a titanium oxide support. Thecatalyst can consist of nickel and nickel oxide on a zinc oxide support.The catalyst can consist of nickel and nickel oxide on a zirconiasupport. The catalyst can consist of nickel and nickel oxide on achromia support.

The catalyst can comprise cobalt on a silica gel support. The catalystcan comprise cobalt on a zeolite support. The catalyst can comprisecobalt on an activated carbon support. The catalyst can comprise cobalton a silicon carbide support. The catalyst can consist essentially ofcobalt on a silica gel support. The catalyst can consist essentially ofcobalt on a zeolite support. The catalyst can consist essentially ofcobalt on an activated carbon support. The catalyst can consistessentially of cobalt on a silicon carbide support. The catalyst canconsist of cobalt on a silica gel support. The catalyst can consist ofcobalt on a zeolite support. The catalyst can consist of cobalt on anactivated carbon support. The catalyst can consist of cobalt on asilicon carbide support.

The catalyst can comprise cobalt on a metal oxide support. The catalystcan consist essentially of cobalt on a metal oxide support. The catalystcan consist of cobalt on a metal oxide support. The catalyst cancomprise cobalt on an alumina support. The catalyst can comprise cobalton a magnesium oxide support. The catalyst can comprise cobalt on atitanium oxide support. The catalyst can comprise cobalt on a zinc oxidesupport. The catalyst can comprise cobalt on a zirconia support. Thecatalyst can comprise cobalt on a chromia support. The catalyst canconsist essentially of cobalt on an alumina support. The catalyst canconsist essentially of cobalt on a magnesium oxide support. The catalystcan consist essentially of cobalt on a titanium oxide support. Thecatalyst can consist essentially of cobalt on a zinc oxide support. Thecatalyst can consist essentially of cobalt on a zirconia support. Thecatalyst can consist essentially of cobalt on a chromia support. Thecatalyst can consist of cobalt on an alumina support. The catalyst canconsist of cobalt on a magnesium oxide support. The catalyst can consistof cobalt on a titanium oxide support. The catalyst can consist ofcobalt on a zinc oxide support. The catalyst can consist of cobalt on azirconia support. The catalyst can consist of cobalt on a chromiasupport.

The catalyst can comprise cobalt oxide on a silica gel support. Thecatalyst can comprise cobalt oxide on a zeolite support. The catalystcan comprise cobalt oxide on an activated carbon support. The catalystcan comprise cobalt oxide on a silicon carbide support. The catalyst canconsist essentially of cobalt oxide on a silica gel support. Thecatalyst can consist essentially of cobalt oxide on a zeolite support.The catalyst can consist essentially of cobalt oxide on an activatedcarbon support. The catalyst can consist essentially of cobalt oxide ona silicon carbide support. The catalyst can consist of cobalt oxide on asilica gel support. The catalyst can consist of cobalt oxide on azeolite support. The catalyst can consist of cobalt oxide on anactivated carbon support. The catalyst can consist of cobalt oxide on asilicon carbide support.

The catalyst can comprise cobalt oxide on a metal oxide support. Thecatalyst can consist essentially of cobalt oxide on a metal oxidesupport. The catalyst can consist of cobalt oxide on a metal oxidesupport. The catalyst can comprise cobalt oxide on an alumina support.The catalyst can comprise cobalt oxide on a magnesium oxide support. Thecatalyst can comprise cobalt oxide on a titanium oxide support. Thecatalyst can comprise cobalt oxide on a zinc oxide support. The catalystcan comprise cobalt oxide on a zirconia support. The catalyst cancomprise cobalt oxide on a chromia support. The catalyst can consistessentially of cobalt oxide on an alumina support. The catalyst canconsist essentially of cobalt oxide on a magnesium oxide support. Thecatalyst can consist essentially of cobalt oxide on a titanium oxidesupport. The catalyst can consist essentially of cobalt oxide on a zincoxide support. The catalyst can consist essentially of cobalt oxide on azirconia support. The catalyst can consist essentially of cobalt oxideon a chromia support. The catalyst can consist of cobalt oxide on analumina support. The catalyst can consist of cobalt oxide on a magnesiumoxide support. The catalyst can consist of cobalt oxide on a titaniumoxide support. The catalyst can consist of cobalt oxide on a zinc oxidesupport. The catalyst can consist of cobalt oxide on a zirconia support.The catalyst can consist of cobalt oxide on a chromia support.

The catalyst can comprise cobalt and cobalt oxide on a silica gelsupport. The catalyst can comprise cobalt and cobalt oxide on a zeolitesupport. The catalyst can comprise cobalt and cobalt oxide on anactivated carbon support. The catalyst can comprise cobalt and cobaltoxide on a silicon carbide support. The catalyst can consist essentiallyof cobalt and cobalt oxide on a silica gel support. The catalyst canconsist essentially of cobalt and cobalt oxide on a zeolite support. Thecatalyst can consist essentially of cobalt and cobalt oxide on anactivated carbon support. The catalyst can consist essentially of cobaltand cobalt oxide on a silicon carbide support. The catalyst can consistof cobalt and cobalt oxide on a silica gel support. The catalyst canconsist of cobalt and cobalt oxide on a zeolite support. The catalystcan consist of cobalt and cobalt oxide on an activated carbon support.The catalyst can consist of cobalt and cobalt oxide on a silicon carbidesupport.

The catalyst can comprise cobalt and cobalt oxide on a metal oxidesupport. The catalyst can consist essentially of cobalt and cobalt oxideon a metal oxide support. The catalyst can consist of cobalt and cobaltoxide on a metal oxide support. The catalyst can comprise cobalt andcobalt oxide on an alumina support. The catalyst can comprise cobalt andcobalt oxide on a magnesium oxide support. The catalyst can comprisecobalt and cobalt oxide on a titanium oxide support. The catalyst cancomprise cobalt and cobalt oxide on a zinc oxide support. The catalystcan comprise cobalt and cobalt oxide on a zirconia support. The catalystcan comprise cobalt and cobalt oxide on a chromia support. The catalystcan consist essentially of cobalt and cobalt oxide on an aluminasupport. The catalyst can consist essentially of cobalt and cobalt oxideon a magnesium oxide support. The catalyst can consist essentially ofcobalt and cobalt oxide on a titanium oxide support. The catalyst canconsist essentially of cobalt and cobalt oxide on a zinc oxide support.The catalyst can consist essentially of cobalt and cobalt oxide on azirconia support. The catalyst can consist essentially of cobalt andcobalt oxide on a chromia support. The catalyst can consist of cobaltand cobalt oxide on an alumina support. The catalyst can consist ofcobalt and cobalt oxide on a magnesium oxide support. The catalyst canconsist of cobalt and cobalt oxide on a titanium oxide support. Thecatalyst can consist of cobalt and cobalt oxide on a zinc oxide support.The catalyst can consist of cobalt and cobalt oxide on a zirconiasupport. The catalyst can consist of cobalt and cobalt oxide on achromia support.

The catalyst can comprise iron on a silica gel support. The catalyst cancomprise iron on a zeolite support. The catalyst can comprise iron on anactivated carbon support. The catalyst can comprise iron on a siliconcarbide support. The catalyst can consist essentially of iron on asilica gel support. The catalyst can consist essentially of iron on azeolite support. The catalyst can consist essentially of iron on anactivated carbon support. The catalyst can consist essentially of ironon a silicon carbide support. The catalyst can consist of iron on asilica gel support. The catalyst can consist of iron on a zeolitesupport. The catalyst can consist of iron on an activated carbonsupport. The catalyst can consist of iron on a silicon carbide support.

The catalyst can comprise iron on a metal oxide support. The catalystcan consist essentially of iron on a metal oxide support. The catalystcan consist of iron on a metal oxide support. The catalyst can compriseiron on an alumina support. The catalyst can comprise iron on amagnesium oxide support. The catalyst can comprise iron on a titaniumoxide support. The catalyst can comprise iron on a zinc oxide support.The catalyst can comprise iron on a zirconia support. The catalyst cancomprise iron on a chromia support. The catalyst can consist essentiallyof iron on an alumina support. The catalyst can consist essentially ofiron on a magnesium oxide support. The catalyst can consist essentiallyof iron on a titanium oxide support. The catalyst can consistessentially of iron on a zinc oxide support. The catalyst can consistessentially of iron on a zirconia support. The catalyst can consistessentially of iron on a chromia support. The catalyst can consist ofiron on an alumina support. The catalyst can consist of iron on amagnesium oxide support. The catalyst can consist of iron on a titaniumoxide support. The catalyst can consist of iron on a zinc oxide support.The catalyst can consist of iron on a zirconia support. The catalyst canconsist of iron on a chromia support.

The catalyst can comprise iron oxide on a silica gel support. Thecatalyst can comprise iron oxide on a zeolite support. The catalyst cancomprise iron oxide on an activated carbon support. The catalyst cancomprise iron oxide on a silicon carbide support. The catalyst canconsist essentially of iron oxide on a silica gel support. The catalystcan consist essentially of iron oxide on a zeolite support. The catalystcan consist essentially of iron oxide on an activated carbon support.The catalyst can consist essentially of iron oxide on a silicon carbidesupport. The catalyst can consist of iron oxide on a silica gel support.The catalyst can consist of iron oxide on a zeolite support. Thecatalyst can consist of iron oxide on an activated carbon support. Thecatalyst can consist of iron oxide on a silicon carbide support.

The catalyst can comprise iron oxide on a metal oxide support. Thecatalyst can consist essentially of iron oxide on a metal oxide support.The catalyst can consist of iron oxide on a metal oxide support. Thecatalyst can comprise iron oxide on an alumina support. The catalyst cancomprise iron oxide on a magnesium oxide support. The catalyst cancomprise iron oxide on a titanium oxide support. The catalyst cancomprise iron oxide on a zinc oxide support. The catalyst can compriseiron oxide on a zirconia support. The catalyst can comprise iron oxideon a chromia support. The catalyst can consist essentially of iron oxideon an alumina support. The catalyst can consist essentially of ironoxide on a magnesium oxide support. The catalyst can consist essentiallyof iron oxide on a titanium oxide support. The catalyst can consistessentially of iron oxide on a zinc oxide support. The catalyst canconsist essentially of iron oxide on a zirconia support. The catalystcan consist essentially of iron oxide on a chromia support. The catalystcan consist of iron oxide on an alumina support. The catalyst canconsist of iron oxide on a magnesium oxide support. The catalyst canconsist of iron oxide on a titanium oxide support. The catalyst canconsist of iron oxide on a zinc oxide support. The catalyst can consistof iron oxide on a zirconia support. The catalyst can consist of ironoxide on a chromia support.

The catalyst can comprise iron and iron oxide on a silica gel support.The catalyst can comprise iron and iron oxide on a zeolite support. Thecatalyst can comprise iron and iron oxide on an activated carbonsupport. The catalyst can comprise iron and iron oxide on a siliconcarbide support. The catalyst can consist essentially of iron and ironoxide on a silica gel support. The catalyst can consist essentially ofiron and iron oxide on a zeolite support. The catalyst can consistessentially of iron and iron oxide on an activated carbon support. Thecatalyst can consist essentially of iron and iron oxide on a siliconcarbide support. The catalyst can consist of iron and iron oxide on asilica gel support. The catalyst can consist of iron and iron oxide on azeolite support. The catalyst can consist of iron and iron oxide on anactivated carbon support. The catalyst can consist of iron and ironoxide on a silicon carbide support.

The catalyst can comprise iron and iron oxide on a metal oxide support.The catalyst can consist essentially of iron and iron oxide on a metaloxide support. The catalyst can consist of iron and iron oxide on ametal oxide support. The catalyst can comprise iron and iron oxide on analumina support. The catalyst can comprise iron and iron oxide on amagnesium oxide support. The catalyst can comprise iron and iron oxideon a titanium oxide support. The catalyst can comprise iron and ironoxide on a zinc oxide support. The catalyst can comprise iron and ironoxide on a zirconia support. The catalyst can comprise iron and ironoxide on a chromia support. The catalyst can consist essentially of ironand iron oxide on an alumina support. The catalyst can consistessentially of iron and iron oxide on a magnesium oxide support. Thecatalyst can consist essentially of iron and iron oxide on a titaniumoxide support. The catalyst can consist essentially of iron and ironoxide on a zinc oxide support. The catalyst can consist essentially ofiron and iron oxide on a zirconia support. The catalyst can consistessentially of iron and iron oxide on a chromia support. The catalystcan consist of iron and iron oxide on an alumina support. The catalystcan consist of iron and iron oxide on a magnesium oxide support. Thecatalyst can consist of iron and iron oxide on a titanium oxide support.The catalyst can consist of iron and iron oxide on a zinc oxide support.The catalyst can consist of iron and iron oxide on a zirconia support.The catalyst can consist of iron and iron oxide on a chromia support.

The catalyst can comprise nickel and cobalt on a silica gel support. Thecatalyst can comprise nickel and cobalt on a zeolite support. Thecatalyst can comprise nickel and cobalt on an activated carbon support.The catalyst can comprise nickel and cobalt on a silicon carbidesupport. The catalyst can consist essentially of nickel and cobalt on asilica gel support. The catalyst can consist essentially of nickel andcobalt on a zeolite support. The catalyst can consist essentially ofnickel and cobalt on an activated carbon support. The catalyst canconsist essentially of nickel and cobalt on a silicon carbide support.The catalyst can consist of nickel and cobalt on a silica gel support.The catalyst can consist of nickel and cobalt on a zeolite support. Thecatalyst can consist of nickel and cobalt on an activated carbonsupport. The catalyst can consist of nickel and cobalt on a siliconcarbide support.

The catalyst can comprise nickel and cobalt on a metal oxide support.The catalyst can consist essentially of nickel and cobalt on a metaloxide support. The catalyst can consist of nickel and cobalt on a metaloxide support. The catalyst can comprise nickel and cobalt on an aluminasupport. The catalyst can comprise nickel and cobalt on a magnesiumoxide support. The catalyst can comprise nickel and cobalt on a titaniumoxide support. The catalyst can comprise nickel and cobalt on a zincoxide support. The catalyst can comprise nickel and cobalt on a zirconiasupport. The catalyst can comprise nickel and cobalt on a chromiasupport. The catalyst can consist essentially of nickel and cobalt on analumina support. The catalyst can consist essentially of nickel andcobalt on a magnesium oxide support. The catalyst can consistessentially of nickel and cobalt on a titanium oxide support. Thecatalyst can consist essentially of nickel and cobalt on a zinc oxidesupport. The catalyst can consist essentially of nickel and cobalt on azirconia support. The catalyst can consist essentially of nickel andcobalt on a chromia support. The catalyst can consist of nickel andcobalt on an alumina support. The catalyst can consist of nickel andcobalt on a magnesium oxide support. The catalyst can consist of nickeland cobalt on a titanium oxide support. The catalyst can consist ofnickel and cobalt on a zinc oxide support. The catalyst can consist ofnickel and cobalt on a zirconia support. The catalyst can consist ofnickel and cobalt on a chromia support.

The catalyst can comprise nickel oxide and cobalt oxide on a silica gelsupport. The catalyst can comprise nickel oxide and cobalt oxide on azeolite support. The catalyst can comprise nickel oxide and cobalt oxideon an activated carbon support. The catalyst can comprise nickel oxideand cobalt oxide on a silicon carbide support. The catalyst can consistessentially of nickel oxide and cobalt oxide on a silica gel support.The catalyst can consist essentially of nickel oxide and cobalt oxide ona zeolite support. The catalyst can consist essentially of nickel oxideand cobalt oxide on an activated carbon support. The catalyst canconsist essentially of nickel oxide and cobalt oxide on a siliconcarbide support. The catalyst can consist of nickel oxide and cobaltoxide on a silica gel support. The catalyst can consist of nickel oxideand cobalt oxide on a zeolite support. The catalyst can consist ofnickel oxide and cobalt oxide on an activated carbon support. Thecatalyst can consist of nickel oxide and cobalt oxide on a siliconcarbide support.

The catalyst can comprise nickel oxide and cobalt oxide on a metal oxidesupport. The catalyst can consist essentially of nickel oxide and cobaltoxide on a metal oxide support. The catalyst can consist of nickel oxideand cobalt oxide on a metal oxide support. The catalyst can comprisenickel oxide and cobalt oxide on an alumina support. The catalyst cancomprise nickel oxide and cobalt oxide on a magnesium oxide support. Thecatalyst can comprise nickel oxide and cobalt oxide on a titanium oxidesupport. The catalyst can comprise nickel oxide and cobalt oxide on azinc oxide support. The catalyst can comprise nickel oxide and cobaltoxide on a zirconia support. The catalyst can comprise nickel oxide andcobalt oxide on a chromia support. The catalyst can consist essentiallyof nickel oxide and cobalt oxide on an alumina support. The catalyst canconsist essentially of nickel oxide and cobalt oxide on a magnesiumoxide support. The catalyst can consist essentially of nickel oxide andcobalt oxide on a titanium oxide support. The catalyst can consistessentially of nickel oxide and cobalt oxide on a zinc oxide support.The catalyst can consist essentially of nickel oxide and cobalt oxide ona zirconia support. The catalyst can consist essentially of nickel oxideand cobalt oxide on a chromia support. The catalyst can consist ofnickel oxide and cobalt oxide on an alumina support. The catalyst canconsist of nickel oxide and cobalt oxide on a magnesium oxide support.The catalyst can consist of nickel oxide and cobalt oxide on a titaniumoxide support. The catalyst can consist of nickel oxide and cobalt oxideon a zinc oxide support. The catalyst can consist of nickel oxide andcobalt oxide on a zirconia support. The catalyst can consist of nickeloxide and cobalt oxide on a chromia support.

The catalyst can comprise nickel and iron on a silica gel support. Thecatalyst can comprise nickel and iron on a zeolite support. The catalystcan comprise nickel and iron on an activated carbon support. Thecatalyst can comprise nickel and iron on a silicon carbide support. Thecatalyst can consist essentially of nickel and iron on a silica gelsupport. The catalyst can consist essentially of nickel and iron on azeolite support. The catalyst can consist essentially of nickel and ironon an activated carbon support. The catalyst can consist essentially ofnickel and iron on a silicon carbide support. The catalyst can consistof nickel and iron on a silica gel support. The catalyst can consist ofnickel and iron on a zeolite support. The catalyst can consist of nickeland iron on an activated carbon support. The catalyst can consist ofnickel and iron on a silicon carbide support.

The catalyst can comprise nickel and iron on a metal oxide support. Thecatalyst can consist essentially of nickel and iron on a metal oxidesupport. The catalyst can consist of nickel and iron on a metal oxidesupport. The catalyst can comprise nickel and iron on an aluminasupport. The catalyst can comprise nickel and iron on a magnesium oxidesupport. The catalyst can comprise nickel and iron on a titanium oxidesupport. The catalyst can comprise nickel and iron on a zinc oxidesupport. The catalyst can comprise nickel and iron on a zirconiasupport. The catalyst can comprise nickel and iron on a chromia support.The catalyst can consist essentially of nickel and iron on an aluminasupport. The catalyst can consist essentially of nickel and iron on amagnesium oxide support. The catalyst can consist essentially of nickeland iron on a titanium oxide support. The catalyst can consistessentially of nickel and iron on a zinc oxide support. The catalyst canconsist essentially of nickel and iron on a zirconia support. Thecatalyst can consist essentially of nickel and iron on a chromiasupport. The catalyst can consist of nickel and iron on an aluminasupport. The catalyst can consist of nickel and iron on a magnesiumoxide support. The catalyst can consist of nickel and iron on a titaniumoxide support. The catalyst can consist of nickel and iron on a zincoxide support. The catalyst can consist of nickel and iron on a zirconiasupport. The catalyst can consist of nickel and iron on a chromiasupport.

The catalyst can comprise nickel oxide and iron oxide on a silica gelsupport. The catalyst can comprise nickel oxide and iron oxide on azeolite support. The catalyst can comprise nickel oxide and iron oxideon an activated carbon support. The catalyst can comprise nickel oxideand iron oxide on a silicon carbide support. The catalyst can consistessentially of nickel oxide and iron oxide on a silica gel support. Thecatalyst can consist essentially of nickel oxide and iron oxide on azeolite support. The catalyst can consist essentially of nickel oxideand iron oxide on an activated carbon support. The catalyst can consistessentially of nickel oxide and iron oxide on a silicon carbide support.The catalyst can consist of nickel oxide and iron oxide on a silica gelsupport. The catalyst can consist of nickel oxide and iron oxide on azeolite support. The catalyst can consist of nickel oxide and iron oxideon an activated carbon support. The catalyst can consist of nickel oxideand iron oxide on a silicon carbide support.

The catalyst can comprise nickel oxide and iron oxide on a metal oxidesupport. The catalyst can consist essentially of nickel oxide and ironoxide on a metal oxide support. The catalyst can consist of nickel oxideand iron oxide on a metal oxide support. The catalyst can comprisenickel oxide and iron oxide on an alumina support. The catalyst cancomprise nickel oxide and iron oxide on a magnesium oxide support. Thecatalyst can comprise nickel oxide and iron oxide on a titanium oxidesupport. The catalyst can comprise nickel oxide and iron oxide on a zincoxide support. The catalyst can comprise nickel oxide and iron oxide ona zirconia support. The catalyst can comprise nickel oxide and ironoxide on a chromia support. The catalyst can consist essentially ofnickel oxide and iron oxide on an alumina support. The catalyst canconsist essentially of nickel oxide and iron oxide on a magnesium oxidesupport. The catalyst can consist essentially of nickel oxide and ironoxide on a titanium oxide support. The catalyst can consist essentiallyof nickel oxide and iron oxide on a zinc oxide support. The catalyst canconsist essentially of nickel oxide and iron oxide on a zirconiasupport. The catalyst can consist essentially of nickel oxide and ironoxide on a chromia support. The catalyst can consist of nickel oxide andiron oxide on an alumina support. The catalyst can consist of nickeloxide and iron oxide on a magnesium oxide support. The catalyst canconsist of nickel oxide and iron oxide on a titanium oxide support. Thecatalyst can consist of nickel oxide and iron oxide on a zinc oxidesupport. The catalyst can consist of nickel oxide and iron oxide on azirconia support. The catalyst can consist of nickel oxide and ironoxide on a chromia support.

The catalyst can comprise cobalt and iron on a silica gel support. Thecatalyst can comprise cobalt and iron on a zeolite support. The catalystcan comprise cobalt and iron on an activated carbon support. Thecatalyst can comprise cobalt and iron on a silicon carbide support. Thecatalyst can consist essentially of cobalt and iron on a silica gelsupport. The catalyst can consist essentially of cobalt and iron on azeolite support. The catalyst can consist essentially of cobalt and ironon an activated carbon support. The catalyst can consist essentially ofcobalt and iron on a silicon carbide support. The catalyst can consistof cobalt and iron on a silica gel support. The catalyst can consist ofcobalt and iron on a zeolite support. The catalyst can consist of cobaltand iron on an activated carbon support. The catalyst can consist ofcobalt and iron on a silicon carbide support.

The catalyst can comprise cobalt and iron on a metal oxide support. Thecatalyst can consist essentially of cobalt and iron on a metal oxidesupport. The catalyst can consist of cobalt and iron on a metal oxidesupport. The catalyst can comprise cobalt and iron on an aluminasupport. The catalyst can comprise cobalt and iron on a magnesium oxidesupport. The catalyst can comprise cobalt and iron on a titanium oxidesupport. The catalyst can comprise cobalt and iron on a zinc oxidesupport. The catalyst can comprise cobalt and iron on a zirconiasupport. The catalyst can comprise cobalt and iron on a chromia support.The catalyst can consist essentially of cobalt and iron on an aluminasupport. The catalyst can consist essentially of cobalt and iron on amagnesium oxide support. The catalyst can consist essentially of cobaltand iron on a titanium oxide support. The catalyst can consistessentially of cobalt and iron on a zinc oxide support. The catalyst canconsist essentially of cobalt and iron on a zirconia support. Thecatalyst can consist essentially of cobalt and iron on a chromiasupport. The catalyst can consist of cobalt and iron on an aluminasupport. The catalyst can consist of cobalt and iron on a magnesiumoxide support. The catalyst can consist of cobalt and iron on a titaniumoxide support. The catalyst can consist of cobalt and iron on a zincoxide support. The catalyst can consist of cobalt and iron on a zirconiasupport. The catalyst can consist of cobalt and iron on a chromiasupport.

The catalyst can comprise cobalt oxide and iron oxide on a silica gelsupport. The catalyst can comprise cobalt oxide and iron oxide on azeolite support. The catalyst can comprise cobalt oxide and iron oxideon an activated carbon support. The catalyst can comprise cobalt oxideand iron oxide on a silicon carbide support. The catalyst can consistessentially of cobalt oxide and iron oxide on a silica gel support. Thecatalyst can consist essentially of cobalt oxide and iron oxide on azeolite support. The catalyst can consist essentially of cobalt oxideand iron oxide on an activated carbon support. The catalyst can consistessentially of cobalt oxide and iron oxide on a silicon carbide support.The catalyst can consist of cobalt oxide and iron oxide on a silica gelsupport. The catalyst can consist of cobalt oxide and iron oxide on azeolite support. The catalyst can consist of cobalt oxide and iron oxideon an activated carbon support. The catalyst can consist of cobalt oxideand iron oxide on a silicon carbide support.

The catalyst can comprise cobalt oxide and iron oxide on a metal oxidesupport. The catalyst can consist essentially of cobalt oxide and ironoxide on a metal oxide support. The catalyst can consist of cobalt oxideand iron oxide on a metal oxide support. The catalyst can comprisecobalt oxide and iron oxide on an alumina support. The catalyst cancomprise cobalt oxide and iron oxide on a magnesium oxide support. Thecatalyst can comprise cobalt oxide and iron oxide on a titanium oxidesupport. The catalyst can comprise cobalt oxide and iron oxide on a zincoxide support. The catalyst can comprise cobalt oxide and iron oxide ona zirconia support. The catalyst can comprise cobalt oxide and ironoxide on a chromia support. The catalyst can consist essentially ofcobalt oxide and iron oxide on an alumina support. The catalyst canconsist essentially of cobalt oxide and iron oxide on a magnesium oxidesupport. The catalyst can consist essentially of cobalt oxide and ironoxide on a titanium oxide support. The catalyst can consist essentiallyof cobalt oxide and iron oxide on a zinc oxide support. The catalyst canconsist essentially of cobalt oxide and iron oxide on a zirconiasupport. The catalyst can consist essentially of cobalt oxide and ironoxide on a chromia support. The catalyst can consist of cobalt oxide andiron oxide on an alumina support. The catalyst can consist of cobaltoxide and iron oxide on a magnesium oxide support. The catalyst canconsist of cobalt oxide and iron oxide on a titanium oxide support. Thecatalyst can consist of cobalt oxide and iron oxide on a zinc oxidesupport. The catalyst can consist of cobalt oxide and iron oxide on azirconia support. The catalyst can consist of cobalt oxide and ironoxide on a chromia support.

The catalyst may be in the form of beads, pellets, extrudates, powder,spheres, or mesh. Preferably, the catalyst comprises nickel on analumina support. More preferably, the catalyst comprises nickel on analumina support in the form of pellets. Most preferably, the catalystcomprises nickel on an alumina support in the form of pellets having adiameter ranging from about 1 mm to about 7 mm.

The catalyst is commercially available. Various loadings (weightpercentages) of nickel metal supported on alumina can be obtained fromHoneywell UOP, Des Plaines, IL, USA or Johnson Matthey, London, UK, forexample.

The weight percentage of the catalyst, as a percentage of the totalweight of the catalyst and the support, may be as little as about 0.1weight percent (wt.%), about 1 wt.%, about 3 wt.%, about 5 wt.%, about10 wt.%, about 15%, or about 20 wt.%, or as high as about 35 wt.%, about40 wt.%, about 45 wt.%, or about 50 wt.%, or within any range definedbetween any two of the foregoing values, such as about 0.1 wt.% to about50 wt.%, about 3 wt.% to about 45 wt.%, about 10 wt.% to about 40 wt.%,about 15 wt.% to about 35 wt.%, or about 3 wt.% to about 25 wt.%, forexample. Preferably, weight percentage of the catalyst is from about 5wt.% to about 45 wt.%. More preferably, the weight percentage of thecatalyst is from about 10 wt.% to about 40 wt.%. Most preferably, theweight percentage of the catalyst is from about 15 wt.% to about 35wt.%.

The catalyst may have a surface area as small as about 1 square metersper gram (m²/g), about 5 m²/g, about 10 m²/g, about 25 m²/g, about 40m²/g, about 60 m²/g, or about 80 m²/g, or as large as about 100 m²/g,about 120 m²/g, about 150 m²/g, about 200 m²/g, about 250 m²/g, about300 m²/g, or about 1,000 m²/g, or within any range defined between anytwo of the foregoing values, such as about 1 m²/g to about 1,00 m²/g,about 5 m²/g to about 300 m²/g, about 10 m²/g to about 250 m²/g, about25 m²/g to about 200 m²/g, about 40 m²/g to about 150 m²/g, about 60m²/g to about 120 m²/g, or about 80 m²/g to about 120 m²/g, for example.The surface area of the catalyst is determined by the BET method per ISO9277:2010.

The reactant stream may be in contact with the catalyst for a contacttime as short as about 0.1 second, about 2 seconds, about 4 seconds,about 6 seconds, about 8 seconds, about 10 seconds, about 15 seconds,about 20 seconds, about 25 seconds, or about 30 seconds, or as long asabout 40 seconds, about 50 seconds, about 60 seconds, about 70 seconds,about 80 seconds, about 100 seconds, about 120 seconds, about 200seconds, or about 1,800 seconds or within any range defined between anytwo of the foregoing values, such as about 0.1 seconds to about 1,800seconds, about 2 seconds to about 120 seconds, about 4 second to about100 seconds, about 6 seconds to about 80 seconds, about 8 seconds toabout 70 seconds, about 10 seconds to about 60 seconds, about 15 secondsto about 50 seconds, about 20 seconds to about 40 seconds, about 20seconds to about 30 seconds, about 10 seconds to about 20 seconds, orabout 100 seconds to about 120 seconds, for example. Preferably, thereactant stream is in contact with the catalyst for a contact time fromabout 2 seconds to about 200 seconds. More preferably, the reactantstream is in contact with the catalyst for a contact time from about 40seconds to about 100 seconds. Most preferably, the reactant stream is incontact with the catalyst for a contact time from about 60 seconds toabout 80 seconds.

The reactant stream and the catalyst may be pre-heated to a reactiontemperature. The reaction temperature may be as low as about 150° C.,about 200° C., about 250° C., about 280° C., about 290° C., about 300°C., about 310° C., or about 320° C., or to a reaction temperature ashigh as about 330° C., about 340° C., about 350° C., about 360° C.,about 380° C., about 400° C., about 450° C., about 500° C., about 550°C., or about 600° C., or within any range defined between any two of theforegoing values, such as about 150° C. to about 600° C., about 200° C.to about 550° C., about 250° C. to about 500° C., about 280° C. to about450° C., about 290° C. to about 400° C., about 300° C. to about 380° C.,about 310° C. to about 360° C., about 320° C. to about 350° C., or about320° C. to about 340° C., for example. Preferably, the reactiontemperature is from about 200° C. to about 500° C. More preferably, thereaction temperature is from about 300° C. to about 400° C. Mostpreferably, the reaction temperature is from about 300° C. to about 350°C.

The hydrogen in the flow of reactants to the reactor will reduce acatalyst including nickel oxide, cobalt oxide, and/or iron oxide to thecorresponding metal. Preferably, such catalysts are reduced by a flow ofhydrogen through the reactor prior to the reaction to reduce thecatalyst to the corresponding metal.

An operating pressure of the reactor may be as low as about 10 kPag(kilo Pascals, gauge pressure), about 50 kPag, about 100 kPag, about 200kPag, about 300 kPag, about 400 kPag or about 600 kPag, or as high asabout 800 kPag, about 1,000 kPag, about 1,500 kPag, about 2,000 kPag,about 2,500 kPag, about 3,000 kPag, or about 4,000 kPag, or within anyrange defined between any two of the foregoing values, such as about 10kPag to about 4,000 kPag, about 50 kPag to about 3,000 kPag, about 100kPag to about 2,500 kPag, about 200 kPag to about 2,000 kPag, about 300kPag to about 1,500 kPag, about 400 kPag to about 1,000 kPag, about 600kPag to about 800 kPag, or about 10 kPag to about 800 kPag, for example.Preferably, the operating pressure of the reactor is from about 10 kPag,to about 800 kPag. More preferably, the operating pressure of thereactor is from about 10 kPag to about 400 kPag. Most preferably, theoperating pressure of the reactor is from about 10 kPag to about 200kPag.

The iodine is provided to the reactor from solid iodine continuously orintermittently added to a heated iodine liquefier to maintain certainlevel of liquid iodine in the liquefier. A positive pressure ismaintained in the liquefier to deliver liquid iodine to an iodinevaporizer. A flow rate of the liquid iodine may be provided bymonitoring the weight loss of a vessel providing the iodine, bycalculating based on a pump stroke volume if a pump is used, and/or bypassing the liquid iodine through a flowmeter, for example. Thetemperature of the iodine in the iodine liquefier is maintained suchthat the temperature is high enough to melt iodine, but low enough toavoid vaporizing the iodine. The liquid iodine is vaporized in thevaporizer to form an iodine vapor. The iodine vapor leaving thevaporizer can be mixed with the hydrogen gas from a hydrogen supply toform the reactant stream. Alternatively, or additionally, the hydrogengas from the hydrogen supply may be provided to the iodine vaporizer toassist in the vaporization of the iodine, thus reducing the vaporizationtemperature. In either case, the hydrogen gas may further includerecycled hydrogen gas and hydrogen iodide. The reactant stream ispreheated to the reaction temperature and fed to a reactor that ispreloaded with any of the catalysts described above. Process linesbetween the liquefier and the vaporizer are heat-traced to ensure thatiodine remains liquid in these lines. Process lines carrying the iodinevapor and the hydrogen/iodine vapor mixture are heat-traced to ensurethat the gas phase is maintained. Alternatively, the solid iodine may beprovided to a vessel that both liquefies and vaporizes the iodine toproduce the iodine vapor.

The product stream including hydrogen iodide, unreacted hydrogen, andunreacted iodine is directed from the reactor to one or more iodineremoval vessels in which the product stream is cooled to allow theunreacted iodine to condense to remove at least some of the iodine fromthe product stream to be recycled as a reactant. Optionally, the productstream is directed to a cooler to remove some of the heat from theproduct stream before condensing the unreacted iodine in the one or moreiodine removal vessels. In the one or more iodine removal vessels, theproduct stream may be cooled to a temperature lower than the boilingpoint of iodine, but above the melting point of iodine, to recover theiodine in liquid form. Alternatively, or additionally, the productstream leaving the reactor may be cooled to a temperature lower than themelting point of iodine to recover the iodine in solid form. The productstream may proceed from the one or more iodine removal vessels to one ormore additional iodine removal vessels to remove additional unreactediodine for recycle.

The product stream, which is substantially free of iodine, can bedirected from the one or more iodine removal vessels to a compressor toincrease the pressure of the product stream to a separation pressuresufficient for efficient recovery of unreacted hydrogen. The separationpressure is greater than the operating pressure of the reactor. Theseparation pressure can be as low as about 800 kPag, about 850 kPag,about 900 kPag, about 950 kPag or about 1,000 kPag, or as high as about1,100 kPag, about 1,200 kPag, about 1,300 kPag, about 1,400 kPag orabout 1,500 kPag, or within any range defined between any two of theforegoing values, such as about 800 kPag to about 1,500 kPag, about 850kPag to about 1,400 kPag, about 900 kPag to about 1,300 kPag, about 950kPag to about 1,200 kPag, about 1,000 kPag to about 1,100 kPag, or about900 kPag to about 1,100 kPag, for example. Preferably, the separationpressure is from about 10 kPag to about 2,000 kPag. More preferably, theseparation pressure is from about 300 kPag to about 1,500 kPag. Mostpreferably, the separation pressure is from about 600 kPag to about1,000 kPag.

The compressed product stream is subjected to a one-stage flash coolingor a distillation to recover a liquid stream and a vapor stream. Thevapor stream includes hydrogen and small amounts of hydrogen iodide. Theliquid stream is substantially free of hydrogen and includes thehydrogen iodide, residual iodine and other higher boiling pointsubstances, such as any water. The vapor stream can be recycled to thereactor. The liquid stream is directed to a distillation column toseparate liquid hydrogen iodide in the overhead stream from residualiodine and other higher boiling point substances including any residualwater in the bottom stream. The higher boiling point substances aredirected from the bottom stream of the distillation column for furtherprocessing including iodine recovery and recycle. A vapor vent from theoverhead of the distillation column may be taken as a purge to removeany non-condensable gases, such as hydrogen.

Alternatively, the product stream can be directed from the one or moreiodine removal vessels to a heavies distillation column to separatehigher boiling point substances, such as hydrogen iodide and anyresidual iodine, from lower boiling point substances, such as unreactedhydrogen. The higher boiling point substances are directed from a bottomstream of the heavies distillation column to an iodine recycledistillation column to separate the hydrogen iodide from the residualiodine. An overhead stream of the heavies column including the hydrogenand any residual hydrogen iodide is directed to a product distillationcolumn. A bottom stream of the iodine recycle distillation columnincluding the residual iodine is recycled back to the iodine liquefier.An overhead stream of the iodine recycle column including the hydrogeniodide is directed to the product distillation column to separate thehydrogen iodide from the hydrogen and other non-condensable gases fromthe heavies column and the iodine recycle column. An overhead stream ofthe product column, including hydrogen and residual hydrogen iodide, maybe recycled back to the reactor. A bottom stream of the product columnincludes the purified hydrogen iodide.

In either of the processes described above, additional product columnsmay be added to increase the purity of the hydrogen iodide. The purifiedhydrogen iodide may be passed through an appropriate desiccant to removeany residual moisture before use in subsequent processes, such as any ofthe processes discussed above, for example. The purified hydrogen iodidemay be provided directly to the subsequent processes. Alternatively, oradditionally, the purified hydrogen iodide may be collected in thestorage tank for short term storage before use in subsequent processes.The recycle of iodine and hydrogen results in an efficient process forproducing hydrogen iodide.

The processes for the manufacture of hydrogen iodide (HI) from hydrogen(H₂) and elemental iodine (I₂) that include the use of a nickel, cobalt,iron, nickel oxide, cobalt oxide, and/or iron oxide catalyst supportedon a support according to this disclosure may be batch processes or maybe continuous processes, as described below.

FIG. 1 is a process flow diagram showing an integrated process formanufacturing anhydrous hydrogen iodide. As shown in FIG. 1 , anintegrated process 10 includes material flows of solid iodine 12 andhydrogen gas 14. The solid iodine 12 may be continuously orintermittently added to a solid storage tank 16. A flow of solid iodine18 is transferred, continuously or intermittently, by a solid conveyingsystem (not shown) or by gravity from the solid storage tank 16 to aniodine liquefier 20 where the solid iodine is heated to above itsmelting point but below its boiling point to maintain a level of liquidiodine in the iodine liquefier 20. Although only one liquefier 20 isshown, it is understood that multiple liquefiers 20 may be used in aparallel arrangement. Liquid iodine 22 flows from the iodine liquefier20 to an iodine vaporizer 24. The iodine liquefier 20 may be pressurizedby an inert gas to drive the flow of liquid iodine 22. The inert gas mayinclude nitrogen, argon, or helium, or mixtures thereof, for example.Alternatively, or additionally, the flow of liquid iodine 22 may bedriven by a pump (not shown). The flow rate of the liquid iodine 22 maybe controlled by a liquid flow controller 26. In the iodine vaporizer24, the iodine is heated to above its boiling point to form a flow ofiodine vapor 28.

The flow rate of the hydrogen 14 may be controlled by a gas flowcontroller 30. The flow of iodine vapor 28 and the flow of hydrogen 14are provided to a superheater 36 and heated to the reaction temperatureto form a reactant stream 38. The reactant stream 38 is provided to areactor 40.

The reactant stream 38 reacts in the presence of a catalyst 42 containedwithin the reactor 40 to produce a product stream 44. The catalyst 42may be any of the catalysts described herein. The product stream 44 mayinclude hydrogen iodide, unreacted iodine, unreacted hydrogen and traceamounts of water and other high boiling impurities.

The product stream 44 may be provided to an upstream valve 46. Theupstream valve 46 may direct the product stream 44 to an iodine removalstep. Alternatively, the product stream 44 may pass through a cooler(not shown) to remove some of the heat before being directed to theiodine removal step. In the iodine removal step, a first iodine removaltrain 48 a may include a first iodine removal vessel 50 a and a secondiodine removal vessel 50 b. The product stream 44 may be cooled in thefirst iodine removal vessel 50 a to a temperature below the boilingpoint of the iodine to condense or desublimate at least some of theiodine, separating it from the product stream 44. The product stream 44may be further cooled in the first iodine removal vessel 50 a to atemperature below the melting point of the iodine to separate even moreiodine from the product stream 44, depositing at least some of theiodine within the first iodine removal vessel 50 a as a solid andproducing a reduced iodine product stream 52. The reduced iodine productstream 52 may be provided to the second iodine removal vessel 50 b andcooled to separate at least some more of the iodine from the reducediodine product stream 52 to produce a further crude hydrogen iodideproduct stream 54.

Although the first iodine removal train 48 a consists of two iodineremoval vessels operating in a series configuration, it is understoodthat the first iodine removal train 48 a may include two or more iodineremoval vessels operating in a parallel configuration, more than twoiodine removal vessels operating in a series configuration, or anycombination thereof. It is also understood that the first iodine removaltrain 48 a may consist of a single iodine removal vessel. It is furtherunderstood that any of the iodine removal vessels may include, or be inthe form of, heat exchangers. It is also understood that consecutivevessels may be combined into a single vessel having multiple coolingstages.

The iodine collected in the first iodine removal vessel 50 a may form afirst iodine recycle stream 56 a. Similarly, the iodine collected in thesecond iodine removal vessel 50 b may form a second iodine recyclestream 56 b. Each of the first iodine recycle stream 56 a and the secondiodine recycle stream 56 b may be provided continuously orintermittently to the iodine liquefier 20, as shown, and/or to theiodine vaporizer 24.

In order to provide continuous operation while collecting the iodine insolid form, the upstream valve 46 may be configured to selectivelydirect the product stream 44 to a second iodine removal train 48 b. Thesecond iodine removal train 48 b may be substantially similar to thefirst iodine removal train 48 a, as described above. Once either thefirst iodine removal vessel 50 a or the second iodine removal vessel 50b of the first iodine removal train 48 a accumulates enough solid iodinethat it is beneficial to remove the solid iodine, the upstream valve 46may be selected to direct the product stream 44 from the first iodineremoval train 48 a to the second iodine removal train 48 b. At about thesame time, a downstream valve 58 configured to selectively direct thecrude hydrogen iodide product stream 54 from either of the first iodineremoval train 48 a or the second iodine removal train 48 b may beselected to direct the crude hydrogen iodide product stream 54 from thesecond iodine removal train 48 b so that the process of removing theiodine from the product stream 44 to produce the crude hydrogen iodideproduct stream 54 may continue uninterrupted. Once the product stream 44is no longer directed to the first iodine removal train 48 a, the firstiodine removal vessel 50 a and the second iodine removal vessel 50 b ofthe first iodine removal train 48 a may be heated to above the meltingpoint of the iodine, liquefying the solid iodine so that it may flowthrough the first iodine recycle stream 56 a and the second iodinerecycle stream 56 b of the first iodine removal train 48 a to the iodineliquefier 20.

As the process continues and either of the first iodine removal vessel50 a or the second iodine removal vessel 50 b of the second iodineremoval train 48 b accumulates enough solid iodine that it is beneficialto remove the solid iodine, the upstream valve 46 may be selected todirect the product stream 44 from the second iodine removal train 48 bback to the first iodine removal train 48 a, and the downstream valve 58may be selected to direct the crude hydrogen iodide product stream 54from the first iodine removal train 48 a so that the process of removingthe iodine from the product stream 44 to produce the crude hydrogeniodide product stream 54 may continue uninterrupted. Once the productstream 44 is no longer directed to the second iodine removal train 48 b,the first iodine removal vessel 50 a and the second iodine removalvessel 50 b of the second iodine removal train 48 b may be heated toabove the melting point of the iodine, liquefying the solid iodine sothat it may flow through the first iodine recycle stream 56 a and thesecond iodine recycle stream 56 b of the second iodine removal train 48b to the iodine liquefier 20. By continuing to switch between the firstiodine removal train 48 a and the second iodine removal train 48 b, theunreacted iodine in the product stream 44 may be efficiently andcontinuously removed and recycled.

As described above, the liquid iodine may flow through the first iodinerecycle streams 56 a and the second iodine recycle streams 56 b of thefirst iodine removal train 48 a and the second iodine removal train 48 bto the iodine liquefier 20. Alternatively, the liquid iodine may flowthrough the first iodine recycle streams 56 a and the second iodinerecycle streams 56 b of the first iodine removal train 48 a and thesecond iodine removal train 48 b to the iodine vaporizer 24, bypassingthe iodine liquefier 20 and the liquid flow controller 26.

In the integrated process shown in FIG. 1 , the crude hydrogen iodideproduct stream 54 is provided to a heavies distillation column 60. Theheavies distillation column 60 may be configured for the separation ofhigher boiling point substances, such as hydrogen iodide and residualunreacted iodine, from lower boiling point substances, such as theunreacted hydrogen. A bottom stream 62 including the hydrogen iodide andresidual unreacted iodine from the heavies distillation column 60 may beprovided to an iodine recycle column 64. The iodine recycle column 64may be configured for the separation of the residual unreacted iodinefrom the hydrogen iodide. A bottom stream 66 of the iodine recyclecolumn 64 including the unreacted iodine may be recycled back to theiodine liquefier 20. Alternatively, the bottom stream 66 of the iodinerecycle column 64 including the unreacted iodine may be recycled back tothe iodine vaporizer 24. An overhead stream 68 of the iodine recyclecolumn 64 including the hydrogen iodide may be provided to a productdistillation column 70.

An overhead stream 72 including the hydrogen and residual hydrogeniodide from the heavies distillation column 60 may also be provided tothe product distillation column 70. The product distillation column 70may be configured to separate the unreacted hydrogen from the hydrogeniodide. An overhead stream 74 of the product column 70 including theunreacted hydrogen and residual hydrogen iodide may be recycled back tothe reactor 40. The resulting purified hydrogen iodide product may becollected from a bottom stream 76 of the product column 70.

FIG. 2 is a process flow diagram showing another integrated process formanufacturing anhydrous hydrogen iodide. The integrated process 78 shownin FIG. 2 is the same as the integrated process 10 described above inreference to FIG. 1 up to the production of the crude hydrogen iodideproduct stream 54. In the integrated process 78 of FIG. 2 , the crudehydrogen iodide product stream 54 is provided to a compressor 80 toincrease the pressure of the crude hydrogen iodide product stream 54 tofacilitate the recovery of the hydrogen and the hydrogen iodide. Thecompressor 80 increases the pressure of the crude hydrogen iodideproduct stream 54 to a separation pressure, that is greater than anoperating pressure of the reactor 42 to produce a compressed productstream 82. The compressed product stream 82 is directed to a partialcondenser 84 where it is subjected to a one-stage flash cooling for theseparation of higher boiling point substances, such as hydrogen iodideand trace amounts of residual, unreacted iodine, from lower boilingpoint substances, such as the unreacted hydrogen. An overhead stream 86including hydrogen and residual hydrogen iodide from the partialcondenser 84 may be recycled back to the reactor 40. A bottom stream 88from the partial condenser 84 including the hydrogen iodide, traceamounts of residual unreacted iodine and trace amounts of water may beprovided to a product column 90. The product column 90 may be configuredfor the separation of the residual unreacted iodine, the water and otherhigher boiling compounds from the hydrogen iodide. A bottom stream 92 ofthe product column 90 including the unreacted iodine may be recycledback to the iodine liquefier 20. Alternatively, the bottom stream 92 ofthe product column 90 including the unreacted iodine may be recycledback to the iodine vaporizer 24. The resulting purified hydrogen iodideproduct may be collected from an overhead stream 94 of the productcolumn 90. A purge stream 96 may be taken from the product column 90 tocontrol the build-up of low boiling impurities. A portion of the purgestream 96 may be recycled back to the reactor 40, while another portionmay be disposed of.

While this invention has been described as relative to exemplarydesigns, the present invention may be further modified within the spiritand scope of this disclosure. Further, this application is intended tocover such departures from the present disclosure as come within knownor customary practice in the art to which this invention pertains.

As used herein, the phrase “within any range defined between any two ofthe foregoing values” literally means that any range may be selectedfrom any two of the values listed prior to such phrase regardless ofwhether the values are in the lower part of the listing or in the higherpart of the listing. For example, a pair of values may be selected fromtwo lower values, two higher values, or a lower value and a highervalue.

EXAMPLES Example 1: Preparation of Hydrogen Iodide From Hydrogen andIodine Catalyzed by Nickel Catalysts

In Example 1, the manufacture of hydrogen iodide (HI) from hydrogen (H₂)and elemental iodine (I₂) according to Equation 3 describe above wasdemonstrated using alumina supported nickel catalysts over a range ofreaction conditions. The catalyst in a fixed bed tubular reactor wasactivated prior to introduction of the mixture of hydrogen gas andiodine vapor into the reactor. The catalyst was activated by purging thecatalyst with nitrogen gas, followed by introducing hydrogen gas,heating the reactor to 120° C., holding for two hours, and then rampingup the reactor temperature to 230° C. and holding for an additionalhour. The reactor temperature was then adjusted to the desired reactiontemperature. A predetermined fixed flow rate of hydrogen was bubbledinto an iodine vaporizer which was initially charged with apredetermined amount of solid elemental iodine. The iodine vaporizertemperature was controlled at between 150° C. and 170° C., whichgenerated iodine vapor. The vaporizer temperature and the hydrogen flowrate were adjusted accordingly to attain the desired mole ratio ofhydrogen to iodine. The mixture of hydrogen and iodine vapor was fedinto the reactor to react in the presence of the catalyst to formhydrogen iodide. The reactor effluent was then passed through atwo-stage iodine collector to collect any unreacted iodine in a solidform. Then, the iodine collector effluent stream containing the crudehydrogen iodide product was collected in a dry ice trap. The effluentstream from the dry ice trap was bubbled through a scrubber charged withdeionized water to capture residual hydrogen iodide from the unreactedhydrogen gas stream. After a predetermined period, the system was shutdown and the iodine vaporizer weight loss and the iodine collectorweight gain was measured to calculate the average H₂/l₂ feed molarratio. Residence time was calculated based on the combined feed rate ofhydrogen and iodine, and conversion was calculated based on the amountsof hydrogen iodide collected and iodine fed to the reactor.

All reactions were carried out in the range of 0-5 psig. The runs usinga 21 wt.% nickel catalyst on the alumina support (Ni/Al₂O₃) each had arun time of 24 hours. The runs using a 20 wt.% Ni/Al₂O₃ or a 5 wt.%Ni/Al₂O₃ catalyst, each run had a run time of 72 hours. Other reactionconditions are shown in Table 1.

The results for each run are shown in Table 1. As shown in Table 1, withthe 21 wt.% nickel catalyst on the alumina support, when the contacttime was greater than 7 seconds, the average conversion was greater than90% and the average productivity was about 35 lb./h/ft³ for reactiontemperatures from about 320° C. to about 360° C. While the 20 wt.%nickel catalyst on the alumina support performed slightly better thanthe 21 wt.% nickel catalyst on the alumina support under comparablereaction conditions, the 5 wt.% nickel catalyst on the alumina supportshowed much lower activity.

TABLE 1 Run No. Catalyst Vaporizer Temp. (°C) I₂ Flow Rate (g/h) H₂ FlowRate (ml/min) H₂/I₂ (mole ratio) Reactor Temp. (°C) Contact Time (s)Conv. (%) HI Productivity (Ib/h/ft³) 1 21 wt.% Ni/ Al₂O₃ (44.5 ml) 15012.7 60 2.99 280 17.7 76.9 13.8 2 150 14.3 60 2.65 300 16.5 88.2 17.9 3160 26.6 120 2.85 320 8.2 89.5 33.7 4 160 27.2 120 2.77 340 7.8 90.034.8 5 160 28.3 120 2.69 350 7.9 89.9 35.9 6 160 28.5 120 2.66 360 7.592.4 37.2 7 160 28.1 120 2.70 370 7.4 92.0 36.5 8 160 28.4 120 2.68 3807.3 90.9 36.4 9 20 wt.% Ni/ Al₂O₃ (100 ml) 170 64.1 240 2.37 330 8.693.8 37.8 10 170 60.3 240 2.52 350 8.4 95.8 36.3 11 5 wt.% Ni/ Al₂O₃(100 ml) 170 65.2 240 2.33 350 8.3 38.4 15.7

Example 2: Effect of H₂/I₂ Mole Ratio in the Preparation of HydrogenIodide From Hydrogen and Iodine Catalyzed by Nickel Catalysts

In Example 2, the effect of H₂/l₂ mole ratio on HI collection rate wasdemonstrated using the 21 wt.% Ni/Al₂O₃ catalyst over a range ofreaction conditions. The same experimental setup and experimentalprocedure as described in Example 1 were used in Example 2, with eachrun having a run time of 24 hours. The HI collection rate was defined asthe percentage of HI collected in the dry ice cold trap with respect tothe total HI generated. As shown in Table 2, the HI collection rate wasabove 90% when the H₂/l₂ mole ratio was 2.7 (below 3), however, withincreasing the H₂/l₂ mole ratio it decreased dramatically. Withoutwishing to be bound by any theory, this suggests that the condensationof HI becomes more difficult in the presence of an excessive amount ofhydrogen.

TABLE 2 Catalyst I₂ rate (g/h) H₂/I₂ (mole ratio) Reaction Temp. (°C)Contact Time (s) l₂ Conv. (%) HI Productivity (lbs/h/ft³) HI CollectionRate (%) 21 wt.% Ni/Al₂O₃ (44.5 ml) 28.08 2.70 370 7.4 92.0 36.5 90.735.46 4.28 320 4.5 80.0 40.0 74.2 36.35 5.92 340 3.2 87.5 44.9 69.731.56 6.42 350 3.4 95.2 42.4 54.5

Aspects

Aspect 1 is a process for producing hydrogen iodide. The processincludes providing a vapor-phase reactant stream comprising hydrogen andiodine, and reacting the reactant stream in the presence of a catalystto produce a product stream comprising hydrogen iodide. The catalystincludes at least one selected from the group of nickel, cobalt, iron,nickel oxide, cobalt oxide, and iron oxide. The catalyst is supported ona support.

Aspect 2 is the process of Aspect 1, wherein in the providing step, thehydrogen comprises less than about 500 ppm by weight of water and lessthan about 500 ppm by weight of oxygen.

Aspect 3 is the process of either of Aspect 1 or Aspect 2, wherein inthe providing step, the iodine comprises less than about 500 ppm byweight of water.

Aspect 4 is the process of any of Aspects 1-3, wherein in the providingstep, a mole ratio of the hydrogen to the iodine in the reaction streamis from about 1:1 to about 10:1.

Aspect 5 is the process of Aspect 4, wherein the mole ratio of thehydrogen to the iodine in the reaction stream is from about 2.5:1 toabout 3:1.

Aspect 6 is the process of any of Aspects 1-5, wherein the support isselected from the group of activated carbon, silica gel, zeolite,silicon carbide, metal oxides, or combinations thereof.

Aspect 7 is the process of Aspect 6, wherein the support is a metaloxide support, the metal oxide support including alumina, magnesiumoxide, titanium oxide, zinc oxide, zirconia, chromia, and combinationsthereof.

Aspect 8 is the process of Aspect 7, wherein the catalyst comprisesnickel and the support is alumina.

Aspect 9 is the process of any of Aspects 1-8, wherein catalyst is fromabout 0.1 wt.% to about 50 wt.% of the total weight of the catalyst andthe support.

Aspect 10 is the process of any of Aspects 1-9, wherein in the reactingstep, a contact time of the reactant stream with the catalyst is fromabout 0.1 second to about 1,800 seconds.

Aspect 11 is the process of any of Aspects 1-10, further comprisingheating the reactant stream to a reaction temperature from about 150° C.to about 600° C. before the reacting step.

Aspect 12 is the process of any of Aspects 1-11, wherein the productstream further comprises unreacted iodine and the process furthercomprises the additional steps of separating the unreacted iodine fromthe product stream as solid iodine, heating the solid iodine to produceliquid iodine, and returning the liquid iodine to the reactant stream.

Aspect 13 is the process of any of Aspects 1-12, wherein the process isa continuous process.

Aspect 14 is the process of any of Aspects 1-13, wherein the productstream further comprises unreacted hydrogen and the process furthercomprises the additional steps of separating the hydrogen from theproduct stream and returning the separated hydrogen to the reactantstream.

Aspect 15 is the process of Aspect 14, wherein separating the hydrogenfrom the product stream includes: compressing the product stream; andsubjecting the compressed product stream to flash cooling.

Aspect 16 is a process for producing hydrogen iodide. The processincludes providing a vapor-phase reactant stream comprising hydrogen andiodine in a mole ratio of the hydrogen to the iodine from about 1:1 toabout 10:1, heating the reactant stream to a reaction temperature fromabout 150° C. to about 600° C., and reacting the reactant stream in thepresence of a catalyst to produce a product stream comprising hydrogeniodide. The catalyst includes at least one selected from the group ofnickel, cobalt, iron, nickel oxide, cobalt oxide, and iron oxide. Thecatalyst is supported on a support. The catalyst is from about 0.1 wt.%to about 50 wt.% of the total weight of the catalyst and the support. Acontact time of the reactant stream with the catalyst is from about 0.1second to about 1,800 seconds.

Aspect 17 is a process for producing hydrogen iodide. The processincludes providing a vapor-phase reactant stream comprising hydrogen andiodine in a mole ratio of the hydrogen to the iodine from about 2:1 toabout 5:1, heating the reactant stream to a reaction temperature fromabout 200° C. to about 500° C., and reacting the reactant stream in thepresence of a catalyst to produce a product stream comprising hydrogeniodide. The catalyst includes at least one selected from the group ofnickel, cobalt and iron. The catalyst is supported on a support. Thecatalyst is from about 5 wt.% to about 45 wt.% of the total weight ofthe catalyst and the support. A contact time of the reactant stream withthe catalyst is from about 2 seconds to about 100 seconds.

Aspect 18 is a process for producing hydrogen iodide. The processincludes providing a vapor-phase reactant stream comprising hydrogen andiodine in a mole ratio of the hydrogen to the iodine from about 2:1 toabout 3:1, heating the reactant stream to a reaction temperature fromabout 300° C. to about 400° C., and reacting the reactant stream in thepresence of a catalyst to produce a product stream comprising hydrogeniodide. The catalyst includes nickel. The catalyst is supported on asupport. The catalyst is from about 10 wt.% to about 40 wt.% of thetotal weight of the catalyst and the support. A contact time of thereactant stream with the catalyst is from about 2 seconds to about 60seconds.

Aspect 19 is a process for producing hydrogen iodide. The processincludes providing a vapor-phase reactant stream comprising hydrogen andiodine in a mole ratio of the hydrogen to the iodine from about 2.5:1 toabout 3:1, heating the reactant stream to a reaction temperature fromabout 300° C. to about 350° C., and reacting the reactant stream in thepresence of a catalyst to produce a product stream comprising hydrogeniodide. The catalyst includes nickel. The catalyst is supported on analumina support. The catalyst is from about 15 wt.% to about 35 wt.% ofthe total weight of the catalyst and the support. A contact time of thereactant stream with the catalyst is from about 2 seconds to about 40seconds.

Aspect 20 is the process of any of Aspects 16-19, wherein in theproviding step, the hydrogen comprises less than about 500 ppm by weightof water and less than about 500 ppm by weight of oxygen, and the iodinecomprises less than about 500 ppm by weight of water.

Aspect 21 is the process of any of Aspects 16-19, wherein in theproviding step, the hydrogen comprises less than about 50 ppm by weightof water and less than about 100 ppm by weight of oxygen, and the iodinecomprises less than about 100 ppm of water.

Aspect 22 is the process of any of Aspects 16-19, wherein in theproviding step, the hydrogen comprises less than about 10 ppm by weightof water and less than about 10 ppm by weight of oxygen, and the iodinecomprises less than about 30 ppm of water.

Aspect 23 is the process of any of Aspects 16-19, wherein in theproviding step, the hydrogen comprises less than about 5 ppm by weightof water and less than about 1 ppm by weight of oxygen, and the iodinecomprises less than about 10 ppm of water.

Aspect 24 is the process of any of Aspects 16-23, wherein the productstream further comprises unreacted iodine and unreacted hydrogen, andthe process further comprises the additional steps of separating theunreacted iodine from the product stream as solid iodine, heating thesolid iodine to produce liquid iodine, returning the liquid iodine tothe reactant stream, separating the hydrogen from the product stream bycompressing the product stream and subjecting the compressed productstream to flash cooling, and returning the separated hydrogen to thereactant stream, wherein the process is a continuous process.

Aspect 25 is the process of any of Aspects 16-23, wherein the productstream further comprises unreacted iodine and unreacted hydrogen, andthe process further comprises the additional steps of separating theunreacted iodine from the product stream as solid iodine, heating thesolid iodine to produce liquid iodine, returning the liquid iodine tothe reactant stream, separating the hydrogen from the product stream bycompressing the product stream and subjecting the compressed productstream to flash cooling, and returning the separated hydrogen to thereactant stream, wherein the process is a batch process.

Aspect 26 is process for producing hydrogen iodide. The process includesthe following steps: reacting hydrogen and iodine in the vapor phase inthe presence of a catalyst to produce a product stream comprisinghydrogen iodide and unreacted iodine, wherein the catalyst comprises atleast one of nickel, cobalt, iron, nickel oxide, cobalt oxide, and ironoxide, and wherein the catalyst is supported on a support; removing atleast some of the unreacted iodine from the product stream by coolingthe product stream to form solid iodine, the solid iodine forming in oneof: a first iodine removal vessel or a second iodine removal vessel;producing liquid iodine from the solid iodine by: heating the firstiodine removal vessel to liquefy the solid iodine when cooling theproduct stream through the second iodine removal vessel, or heating thesecond iodine removal vessel to liquefy the solid iodine when coolingthe product stream through the first iodine removal vessel; andrecycling the liquified iodine to the reacting step.

Aspect 27 is the process of Aspect 26, wherein the product streamfurther comprises unreacted hydrogen and the process further comprisesthe additional steps of: separating the hydrogen from the product streamand recycling the separated hydrogen to the reacting step.

Aspect 28 is the process of Aspect 27, wherein separating the hydrogenfrom the product stream includes: compressing the product stream; andsubjecting the compressed product stream to flash cooling.

Aspect 29 is the process of any of Aspects 26-28, wherein the process isa continuous process.

Aspect 30 is the process of any of Aspects 26-28, wherein the process isa batch process.

Aspect 31 is the process of any of Aspects 26-30, wherein the support isselected from the group of activated carbon, silica gel, zeolite,silicon carbide, metal oxides, or combinations thereof.

Aspect 32 is the process of Aspect 31, wherein the support is a metaloxide support, the metal oxide support including alumina, magnesiumoxide, titanium oxide, zinc oxide, zirconia, chromia, or combinationsthereof.

Aspect 33 is the process of Aspect 32, wherein the catalyst comprisesnickel on an alumina support.

Aspect 34 is the process of any of Aspects 26-33, wherein reactinghydrogen and iodine in the vapor phase in the presence of a catalyst isat a reaction temperature from about 150° C. to about 600° C.

Aspect 35 is process for producing hydrogen iodide. The process includesthe following steps: reacting hydrogen and iodine in the vapor phase ata mole ratio of the hydrogen to the iodine from about 1:1 to about 10:1in the presence of a catalyst a reaction temperature from about 150° C.to about 600° C. and a contact time of from about 0.1 second to about1,800 seconds to produce a product stream comprising hydrogen iodide andunreacted iodine, wherein the catalyst comprises at least one of nickel,cobalt, iron, nickel oxide, cobalt oxide, and iron oxide, the catalystis supported on a support and the catalyst is from about 0.1 wt.% toabout 50 wt.% of the total weight of the catalyst and the support;removing at least some of the unreacted iodine from the product streamby cooling the product stream to form solid iodine, the solid iodineforming in one of: a first iodine removal vessel or a second iodineremoval vessel; producing liquid iodine from the solid iodine by:heating the first iodine removal vessel to liquefy the solid iodine whencooling the product stream through the second iodine removal vessel, orheating the second iodine removal vessel to liquefy the solid iodinewhen cooling the product stream through the first iodine removal vessel;and recycling the liquified iodine to the reacting step.

Aspect 36 is process for producing hydrogen iodide. The process includesthe following steps: reacting hydrogen and iodine in the vapor phase ata mole ratio of the hydrogen to the iodine from about 2:1 to about 5:1in the presence of a catalyst a reaction temperature from about 200° C.to about 500° C. and a contact time of from about 2 seconds to about 100seconds to produce a product stream comprising hydrogen iodide andunreacted iodine, wherein the catalyst comprises at least one of nickel,cobalt and iron, the catalyst is supported on a support and the catalystis from about 5 wt.% to about 45 wt.% of the total weight of thecatalyst and the support; removing at least some of the unreacted iodinefrom the product stream by cooling the product stream to form solidiodine, the solid iodine forming in one of: a first iodine removalvessel or a second iodine removal vessel; producing liquid iodine fromthe solid iodine by: heating the first iodine removal vessel to liquefythe solid iodine when cooling the product stream through the secondiodine removal vessel, or heating the second iodine removal vessel toliquefy the solid iodine when cooling the product stream through thefirst iodine removal vessel; and recycling the liquified iodine to thereacting step.

Aspect 37 is process for producing hydrogen iodide. The process includesthe following steps: reacting hydrogen and iodine in the vapor phase ata mole ratio of the hydrogen to the iodine from about 2:1 to about 3:1in the presence of a catalyst a reaction temperature from about 300° C.to about 400° C. and a contact time of from about 2 seconds to about 60seconds to produce a product stream comprising hydrogen iodide andunreacted iodine, wherein the catalyst comprises nickel, the catalyst issupported on a support and the catalyst is from about 10 wt.% to about40 wt.% of the total weight of the catalyst and the support; removing atleast some of the unreacted iodine from the product stream by coolingthe product stream to form solid iodine, the solid iodine forming in oneof: a first iodine removal vessel or a second iodine removal vessel;producing liquid iodine from the solid iodine by: heating the firstiodine removal vessel to liquefy the solid iodine when cooling theproduct stream through the second iodine removal vessel, or heating thesecond iodine removal vessel to liquefy the solid iodine when coolingthe product stream through the first iodine removal vessel; andrecycling the liquified iodine to the reacting step.

Aspect 38 is process for producing hydrogen iodide. The process includesthe following steps: reacting hydrogen and iodine in the vapor phase ata mole ratio of the hydrogen to the iodine from about 2.5:1 to about 3:1in the presence of a catalyst a reaction temperature from about 300° C.to about 350° C. and a contact time of from about 2 seconds to about 40seconds to produce a product stream comprising hydrogen iodide andunreacted iodine, wherein the catalyst comprises nickel on an aluminasupport and the catalyst is from about 15 wt.% to about 35 wt.% of thetotal weight of the catalyst and the support; removing at least some ofthe unreacted iodine from the product stream by cooling the productstream to form solid iodine, the solid iodine forming in one of: a firstiodine removal vessel or a second iodine removal vessel; producingliquid iodine from the solid iodine by: heating the first iodine removalvessel to liquefy the solid iodine when cooling the product streamthrough the second iodine removal vessel, or heating the second iodineremoval vessel to liquefy the solid iodine when cooling the productstream through the first iodine removal vessel; and recycling theliquified iodine to the reacting step.

Aspect 39 is the process of any of Aspects 35-38, wherein the productstream further comprises unreacted hydrogen and the process furthercomprises the additional steps of: separating the hydrogen from theproduct stream by compressing the product stream and subjecting thecompressed product stream to flash cooling, and recycling the separatedhydrogen to the reacting step; and the process is a continuous process.

Aspect 40 is the process of any of Aspects 35-39, wherein the productstream further comprises unreacted hydrogen and the process furthercomprises the additional steps of: separating the hydrogen from theproduct stream by compressing the product stream and subjecting thecompressed product stream to flash cooling, and recycling the separatedhydrogen to the reacting step; and the process is a batch process.

Aspect 41 is the process of any of Aspects 35-40, wherein the hydrogencomprises less than about 500 ppm by weight of water and less than about500 ppm by weight of oxygen, and the iodine comprises less than about500 ppm of water.

Aspect 42 is the process of any of Aspects 35-41 , wherein the hydrogencomprises less than about 50 ppm by weight of water and less than about100 ppm by weight of oxygen, and the iodine comprises less than about100 ppm of water.

Aspect 43 is the process of any of Aspects 35-42, wherein the hydrogencomprises less than about 10 ppm by weight of water and less than about10 ppm by weight of oxygen, and the iodine comprises less than about 30ppm of water.

Aspect 44 is the process of any of Aspects 35-43, wherein the hydrogencomprises less than about 5 ppm by weight of water and less than about 1ppm by weight of oxygen, and the iodine comprises less than about 10 ppmof water.

What is claimed is:
 1. A process for producing hydrogen iodide, theprocess comprising: providing a vapor-phase reactant stream comprisinghydrogen and iodine; reacting the reactant stream in the presence of acatalyst to produce a product stream comprising hydrogen iodide (HI),unreacted iodine (12) and unreacted hydrogen (H2); separating unreactediodine, condensing a stream comprising hydrogen iodide (HI); andoptionally venting or recycling a stream comprising unreacted hydrogen(H2).
 2. The process of claim 1, wherein separating the unreacted iodinefurther comprises cooling the unreacted iodine, and separating theunreacted iodine from the product stream as solid iodine.
 3. The processof claim 2, further comprising heating the solid iodine to produceliquid iodine; vaporizing the liquid iodine, and returning the vaporizediodine to the reactant stream.
 4. The process of claim 1, comprisingseparating at least some of the unreacted iodine from the product streamby cooling the product stream to form solid iodine, the solid iodineforming in one of: a first iodine removal vessel; or a second iodineremoval vessel; producing liquid iodine from the solid iodine by:heating the first iodine removal vessel to liquefy the solid iodine whencooling the product stream through the second iodine removal vessel; orheating the second iodine removal vessel to liquefy the solid iodinewhen cooling the product stream through the first iodine removal vessel;and recycling the liquified iodine to the reacting step.
 5. The processof claim 3, wherein the process is a continuous process.
 6. The processof claim 1, the process further comprising the additional steps of:separating the unreacted hydrogen from the product stream; and returningthe separated hydrogen to the reactant stream.
 7. The process of claim4, wherein separating the unreacted hydrogen from the product streamincludes: compressing the product stream; and subjecting the compressedproduct stream to flash cooling.
 8. The process of claim 6, wherein theprocess is a continuous process.
 9. The process of claim 7, wherein inthe compressing step, the product stream is compressed to a pressurefrom about 10 kPag to about 2,000 kPag.
 10. The process of claim 7,wherein in the compressing step, the product stream is compressed to apressure from about 300 kPag to about 1.500 kPag.
 11. The process ofclaim 7, wherein in the compressing step, the product stream iscompressed to a pressure from about 600 kPag to about 1,000 kPag. 12.The process of claim 1, wherein the process further comprises theadditional steps of separating the unreacted iodine from the productstream as solid iodine, heating the solid iodine to produce liquidiodine, returning the liquid iodine to the reactant stream, separatingthe hydrogen from the product stream by compressing the product stream,and subjecting the compressed product stream to flash cooling, andreturning the separated hydrogen to the reactant stream, wherein theprocess is a batch process.
 13. The process of claim 1, wherein theprocess further comprises the additional steps of separating theunreacted iodine from the product stream as solid iodine, heating thesolid iodine to produce liquid iodine, returning the liquid iodine tothe reactant stream, separating the hydrogen from the product stream bycompressing the product stream, and subjecting the compressed productstream to flash cooling, and returning the separated hydrogen to thereactant stream, wherein the process is a continuous process.
 14. Theprocess of claim 1, wherein the process comprises reacting hydrogen andiodine in the vapor phase at a mole ratio of the hydrogen to the iodinefrom about 2:1 to about 5:1 in the presence of a catalyst a reactiontemperature from about 200° C. to about 500° C. and a contact time offrom about 2 seconds to about 100 seconds.